Soundproofing Hardwood Floors

My wife and I are considering replacing the carpeted floors in our 3rd floor condo with hardwood. We like our downstairs neighbors and we want to make sure that we don’t increase the noise level they have to put up with. Our current carpet is pretty threadbare and the pad is thin, so we’re hoping that putting in new floors with good soundproofing underneath may actually make things quieter.

Does anybody have any recommendations for what soundproofing material to use? We’ll be talking to our contractor soon, but I’d like to have a general idea what’s available in advance.

Thanks!

Even the best padding/soundproofing layer didn’t do much for us on the second floor of the house. It’s damn loud below, like “a herd of elephants” loud.

In subsequent houses, we have gone with carpet upstairs and hardwood downstairs.

I live on a streetcar line - I think I can speak to this…

When I moved in, the original oak floor was bare. If you have ever seen the inside of a piano (or even an acoustic guitar, you have seen a sounding board - they are used to amplify the sound produced by the strings.
Oak makes a fantastic sounding board.
There are many “soundproofing” products available, but they all (in my experience) are either limited to a specific frequency (Google ‘MLVB’ - a rather expensive product which promises to reduce sound transmission, but only in the range of human voices.
While this is cheaper and easier to install than the product it is intended to replace (sheet lead - yes, lead - soft, high density stuff - it absorbs sound), it will not do much to cut the sound level.
All other products I’ve seen (ever pay $500 for a Home Depo window?) are either nearly useless or very thick - the windows in question are 30" x 54", and TRIPLE glazed - they each weight well over 100 pounds.

Bottom line:
You will not find anything which cuts the noise of a hardwood floor that is less than approx. 4" in thickness - not something you want to put on a floor.

If you wish to pursue this further, the term you need to know is “STC” - Sound Transmission (something) - the massive windows are rated at STC 45 - not “front row at a rock concert”, but it comes close to “1/4 mile from the departure end of the runway at the international airport”.

Good luck.

p.s. - I did not sleep for the first three days of living here, and the first thing I did was to install the thickest carpet on the thickest pad I could afford - that is the noise level of a hardwood floor - the carpeting cut the noise by roughly 30%. I then installed softwood planking on the street side of the living quarters - it did some good, but nowhere near the effect of the carpet and pad.

Is your subfloor concrete or plywood?

It looks like you can put cork or foam padding under laminate floors. Here is a page of MLV products.

Also, you might end up breaking up the floor with area rugs that would absorb some of the noise.

Concrete, I believe. And we’re planning on putting down our oriental rugs. They’re rolled up underneath our bed right now.

If you have concrete floors, then you should have minimal problems, I believe. Concrete is a good sound insulator. Maybe.

Anyhoo, what I was going to say is that when laying laminate flooring, you first lay a foam sheet in order to “float” your floor on top of. You can have regular polystyrne (for general purpose) , a blue material (for dampproofing) or a green material (for soundproofing). In Ireland anyway, colours probably differ where you are, so you can check. Anyrate, it sounds like you are laying a solid floor, which some people will tell you must be nailed into place, or stuck with a gunoprene adhesive. But you can “float” it either, no matter what people tell you. Just tell them Bubastis said you could. So float your wooden floor, using the soundproofing material (on the double if you want to be really safe; its not thick at all, and it will flatten down over time. Its quite spongy). And the concrete is a good sound insulator too.

As Swiss Tony might have said, “Laying a wooden floor is very much like making love to a beautiful woman… Choose a suitable surface, lay her out, line it up, nail it hard.”